Generator monitoring, control and efficiency

ABSTRACT

A system for generating electricity includes a generator and an interface. The generator is coupled to the interface and provides data to the interface regarding electricity generation. The interface is coupled to a control node for monitoring and controlling the generator. The control node may be coupled to the generator through a medium such as the internet. In some aspects of the invention, a continuous emissions monitoring system is provided for fossil-fuel based generators to enhance operation and reduce emissions of such generators.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a Divisional of application Ser. No. 10/079,054, filed Feb. 18,2002 the benefit of earlier-filed co-pending provisional applications:60/269,921 entitled CONTINUOUS EMISSIONS MONITORING SYSTEM FOR DIESELGENERATORS, filed Feb. 19, 2001; 60/270,429 entitled WEB-BASED MICROPOWERPLANT MONITOR AND CONTROL, filed Feb. 21, 2001; 60/272,924 entitledWEB-BASED MICRO POWERPLANT MONITOR AND CONTROL, filed Mar. 2, 2001;60/276,158 entitled CENTRALIZED DISPATCH SYSTEM FOR BACK-UP POWERSYSTEM, filed Mar. 15, 2001; and 60/229,291 entitled POWER GENERATINGMONITORING, CONTROL AND EFFICIENCY, filed Jun. 19, 2001. All of theabove applications are fully incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to monitoring and control of small-scalepower generators.

Worldwide, the demand for energy continues to increase while the supplyof energy, such as electricity, is not always able to keep up with theincreased demand. For instance, recently the west coast of the UnitedStates has been gripped by an energy crisis as the demand for energy,and more specifically electricity, has increased faster thanimprovements in infrastructure and capacity. The result of this was mostpronounced in California where electricity producing plants have beenrunning at virtually maximum capacity in order to provide electricity tothe residents and industry of California. Even running at capacity,there have been rolling brown-outs where entire grids are provided withreduced power for a period of time. In order to remedy this problem,additional electrical power generating plants are required. However, theconstruction of such a large-scale electrical generating facility takesyears to complete and is a very costly process. Thus, there is currentlya dire need in many places, such as the west coast of the United Statesof America, to reduce energy consumption and to increase electricalcapacity.

It is somewhat surprising to learn that even while the power plantsoperating in the western regions of the United States are running atvirtually maximum capacity, they have back-up and peak generators thatsit idle. These idled generators are used to provide additionalelectricity during peak demand. Many of these generators cannot be runfulltime because they are powered by fossil fuel engines such asreciprocating diesel engines, reciprocating gas engines, and gasturbines which generally produce relatively large emissions, especiallyif operated at less than optimal conditions The United StatesEnvironmental Protection Agency (EPA) has promulgated rules such as 40.CFR 60, part 75, that prescribe the maximum emissions that such fossilfuel-based generators can produce. The result of this is that while manyparts of the western United States wrestle with dire electrical capacityand demand, thousands of back-up and peak generators in that very regionsit idle.

Many large facilities also have their own back-up generators to provideback-up electricity for mission critical processes if their own supplyof electricity is interrupted. Examples of such facilities include largecorporations, hospitals, water and waste treatment facilities, shoppingcenters, prisons, universities, and any other facilities where the unitcost of electricity prohibits operation during non-emergency situations.Thus, in such situations, these generators also sit idle. As usedherein, generator includes any system that converts any form of energyinto electrical energy.

Another group of under-utilized generators can be found at facilitiessuch as fast food restaurants, hotels, and other miscellaneousbuildings. Such power systems are not used for back-up but generally runcontinuously or when the business is operating. However, such generatorsare typically oversized and their demanded internal use is periodic(higher when temperature is either higher or lower due to heating or airconditioned needs, higher when more people are in the building, andgenerally not used when the facility is closed). On average, theseresources are operated at less than approximately 50 percent capacity.Large-scale deployment of such generators is significantly limited bythe lack of a cost-effective Continuous Emission Monitoring System(CEMS) solution and the economics of having to buy a system that isoften twice as large as what is required.

There are a number of technical hurdles that must be surmounted beforelarge-scale implementation of available generators can occur. A firstissue relates to emissions from fossil fuel burning generators. Asdescribed above, current continuous operation of such fossil fuelburning generators is limited due to the lack of a suitable emissionsmonitoring system. Another challenge that must be surmounted is thelarge-scale monitoring, control and maintenance of such generators.Further, it is important to improve energy efficiency as much aspossible in order to extract as much usable energy as possible from agiven source.

With respect to the emissions of fossil fuel based generators, it hasbeen long known that fossil fuel engines such as diesel engines, alsoknown as compression ignition engines, have high exhaust emissions.Emissions include carbon soot, carbon dioxide, volatile organiccompounds, hydrocarbons and oxides of nitrogen.

The United States EPA is particularly concerned with emissions of dieselengines and numerous efforts are currently underway to reduce theemissions of such engines. See, for example, U.S. Pat. No. 6,173,567 toPoola et al. Currently, all power generation plants are required torecord emissions and allow the EPA to conduct an on-site audit. Duringthe audit, the EPA reviews emission data and typically requests anemission monitor calibration in their presence. To record anddemonstrate calibration on each generator is an administrative burden.The cost of outfitting, calibrating and demonstrating each generator isone constraint that has heretofore prohibited effective use of suchgenerators.

Regardless of the methods in which fossil fuel engines are controlled,in order to reduce exhaust emissions therefrom, it is generallynecessary to somehow monitor the exhaust emissions themselves to providea closed-loop system. The EPA does allow diesel peak generators tooperate for short periods of time without monitoring of emissions,however this constraint reduces capacity. In electrical power producingplants, Continuous Emission Monitoring Systems (CEMS) are used tocontinuously sample exhaust emissions and analyze them for constituentcomponents.

Currently, the CEMS equipment used for electrical power producing plantsis wholly unsuitable for relatively small-scale generators that sit idleor are underutilized. This is because such current CEMS equipment isextremely unwieldy, often weighing over 300 pounds and requiring specialtransportation and special handling. Further, typical CEMS samplehandling systems require approximately 120 hours of assembly and cancost upwards of $16,000.00. These factors in comparison to the cost andnumber of individual diesel-electric generators renders current CEMSequipment, though technically feasible, wholly impractical for suchsmaller applications.

A continuous emission monitoring system for small-scale fossil fuelgenerator systems that could be easily mounted on such generators andinstalled for a cost that could be justified, would facilitate enhancedemissions monitoring and use of such electrical generators. Monitoringthe operation of the generators would facilitate compliance with currentUnited States Environmental Protection Agency Guidelines, therebyallowing such generators to operate full time if need be. One potentialuse would be to allow the tens of thousands of smaller scale generatorsto assist in transition times where large-scale electrical generationplants are under construction. Further, the various corporationsemploying such generators could produce electricity with such generatorsand sell their excess electricity back to the energy or utilitycompanies for transmission to others. The advantages provided by thesegenerators will only increase as technical advances are made to reducethe emissions of diesel engines and improve diesel fuels.

As discussed above, management and control of such generators alsopresents a challenge. Specifically, in order to effectively utilize thecapacity provided by such generators, it is important to be able tomanage such devices without having to manually monitor and adjust eachand every generator during operation to comply with EPA regulations. Itis also important to be able to monitor emissions from fossil-fuel basedgenerators without being present at the generator's location, given thatsuch generators may number in the thousands.

Further, the economics of large-scale implementation of such generatorsand controllers would be improved if the efficiency of such systemscould be improved. For example, it would be beneficial if the waste heatflowing from the generator itself could be put to additional use.

SUMMARY OF THE INVENTION

An improved continuous emissions monitoring system is disclosed that hasbeen adapted for use with the fossil fuel burning generators. Theimproved sample handling system for the continuous emissions monitoringemission monitoring system is much smaller than traditional samplehandling systems while also significantly less expensive than such priorsystems and can be set up in significantly less time that than thatrequired for prior systems. These features will become apparent withreference to the various embodiments set forth below.

In another aspect of the invention, the generators are controlledthrough a centralized controller that provides control and reportingfunctions allowing cost reductions, associated with operation of suchgenerators. In one embodiment, the dispatch, control, monitoring andoptimization of such generators is done through communication means,such as the internet, an intranet, a virtual LAN, wirelesscommunication, or any other suitable medium.

In yet another aspect of the invention, waste heat from the generator isrecaptured and used to drive a metal hydride type heat pump system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of a continuous emissions monitoringsystem.

FIG. 2 is a diagrammatic view of a typical sample handling system.

FIG. 3 is a diagrammatic view of a sample handling system in accordancewith an embodiment of the present invention.

FIG. 4 is a diagrammatic view of an analyzer in accordance with anembodiment of the present invention.

FIG. 5 is a diagrammatic view of a power generation system in accordancewith an embodiment of the present invention.

FIG. 6 is a diagrammatic view of a system for monitoring and controllingmultiple power generating systems in accordance with an embodiment ofthe present invention.

FIG. 7 is a diagrammatic view of a power generating system and heat pumpsystem operating in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments is organized byfunction. However, the organization of the description should not beconsidered a limitation upon the invention, since various functions canbe combined or omitted as desired.

Continuous Emission Monitoring System (CEMS)

FIG. 1 illustrates a Continuous Emission Monitoring System 10 coupled toa process container such as pipe 12. System 10 periodically, orcontinuously, extracts samples of exhaust gas from container 12 andanalyzes such gases for constituent components. Based upon the analysisof such components, information can be obtained about the combustionprocess itself. Once this information is known, various parameters canbe adjusted or modified in order to optimize the combustion process.Generally, a Continuous Emission Monitoring System, such as system 10,includes two main components; a sample handling system and a suitableanalyzer.

Sample handling system 14 is coupled to an analyzer 16 and is used toextract a process sample from a sampling point on process container 12.Generally, a sample handling system includes all requisite components tomaintain a constant sample flow to analyzer 16. Thus, the samplehandling system generally includes suitable pressure reductioncomponents, filters, vaporizes, flow controls, and sample switching orselector valves for introducing multiple sample streams or calibrationstandards to the process analyzer. Sample handling systems are animportant component of effective emission monitoring systems because ifthe emission sample is not delivered to the analyzer in a condition thatis representative of the combustion, errors will occur in the analysis.Many of the problems encountered in emission monitoring systems can betraced to problems occurring in the sample handling systems.

Once the emissions sample is extracted from container 12, it is providedto analyzer 16 for quantitative analysis. Analyzer 16 can include anysuitable sensors and measurement techniques in order to generallyquantify the presence of oxygen, oxides of nitrogen, soot, volatileorganic compounds, and other substances as desired. The output ofanalyzer 16 can be provided to a control system (which will be describedin greater detail later in the specification) that makes decisions basedupon the quantitative analysis and allows closed-loop control of thecombustion process. For example, a parameter such as combustion airmight be controlled based upon carbon monoxide content in the exhauststream. In this manner, Continuous Emission Monitoring Systems are usedto reduce emissions generated by sources by adjusting operatingparameters to increase efficiency, or identify fault conditions whichrequire repairs or system shut-down.

FIG. 2 is a diagrammatic view of a prior art sample handling systemgenerally used with Continuous Emission Monitoring Systems. Samplehandling system 20 receives dry, oil-free instrument air at valve 22which air is conveyed to pressure regulators 24 and 26. The regulatedair from regulator 24 is provided to solenoid valve 28 which solenoidvalve is controlled by energization signals from blow-back timer 30. Theregulated output from pressure regulator 26 is provided to solenoidvalve 32 which operates based upon an energization signal received fromblow-back timer 30. The selectable air output from solenoid valve 32operates four-way pneumatic valve 34 while the output from solenoidvalve 28 provides blow-back through pneumatic four-way valve 34.Pneumatic four-way valve 34 is coupled to sample probe 36 which isadapted to couple to an emission source and receive a sample therefrom.The sample is conveyed through pneumatic four-way valve 34 tothermoelectric cooler 38 via a heated sample line 40.

Heated sample line 40 is maintained at a temperature of approximately250° F. in order to inhibit condensation of the sample flow. Since thisline is heated, it is relatively costly to provide and often costs inthe range of $50.00 per foot. This cost, coupled with the fact thattypical heated sample line is approximately 100 to 200 feet long inorder to span the distance between the sample handling system and theanalyzer, creates a significant cost for the sample handling system.Once the heated sample is conveyed to thermoelectric cooler 38, thesample is cooled and condensation is allowed to drain through line 42which is assisted by peristaltic pump 44. The cooled sample is conveyedfrom thermoelectric cooler 38 to thermoelectric cooler 46 via line 48and the assistance of sample pump 50. As with thermoelectric cooler 38,condensation from thermoelectric cooler 46 is drained via line 52 andthe assistance of peristaltic pump 44. The doubly-cooled sample isprovided from thermoelectric cooler 46 through filter 54, throughselector valve 56, flow meter 58, and filter 60 to analyzer 16. Sourcesof span gas 64 and zero gas 66 are also provided to selector valve 56 aswell as pneumatic four-way valve 34. These gases are used to provideknown quantities to the analyzer to establish analyzer calibration. Thecomplexity and costs of such a system make it not readily applicable tosmall scale operations such as for diesel generators.

Generally, system 20 includes two enclosures. The first enclosure isprovided at the sample point on the stack or exhaust port and isgenerally sized to be approximately 24 inches high by 24 inches wide by10 inches deep and is of standard design. This enclosure is generallyheated to 250° F. plus or minus approximately 10° F. The first enclosuregenerally includes the sample probe, four-way valve which is airoperated for blow-back and auto-calibration, as well as the solenoidvalve. The second enclosure of system 20 is generally sized to beapproximately 72 inches high by 24 inches high by 30 inches deep and isalso generally of NEMA 4 design. The second enclosure generally includesboth thermoelectric coolers, the peristaltic pumps for water drainage,the diaphragm pump for back pressure, the valves, filters, solenoidvalves for auto-calibration with check valves, pressure regulators withpressure gauges for the four-way valve operation and for sampleblow-back, and the flowmeter. Thus, it is apparent that the heatedsample is conveyed from the first enclosure to the second enclosure andthus a suitable amount of heated sample line must be conveyed to spanthe distance between these two enclosures. This is a costly processsince a typical span can range between 100 and 200 feet. At $50.00/foot,the tubing alone can cost between five and ten thousand dollars.

FIG. 3 is a diagrammatic view of an improved sample handling system 70in accordance with an embodiment of the present invention. System 70 isprovided within a single enclosure 72 which enclosure 72 is divided intoportions 74 and 76. Preferably enclosure 72 is sized to be approximately24 inches by 24 inches by 10 inches and of NEMA 4 design. Due to thesize of enclosure 72, it can be mounted on top of an emissions stack. Itis appreciated that enclosure 72 can be mounted on an exhaust port at avariety of locations. Portion 74 of enclosure 72 is maintained at anelevated temperature, such as 250° F., by heater element 78 operating inconjunction with feedback from temperature sensor 80. A suitable sampleprobe 82 is operably coupled to a source of emissions such as via pipe84 and the sample is conveyed through four-way valve 86, through filter88, to thermoelectric cooler 90. Four-way valve 86 is also coupled to apressurized source of air or nitrogen for blow-back. Preferably, thepressurized source of air or nitrogen is provided at approximately 30pounds per square inch gauge (PSIG). Although four-way valve 86 can be aconventional pneumatic four-way valve, it can also be a cost-effectivechromatograph multi-position valve. The pressurized air/nitrogen isconveyed through pressure regulator 90 and solenoid valve 92, both ofwhich are generally disposed within portion 76 of housing 72. As such,blow-back air can be selectively provided through four-way 86. Thoseskilled in the art will recognize since all components of system 70 areprovided within a single enclosure 72, certain synergies can beachieved. Specifically, where previously four-way valve 86 was apneumatic valve operated by pneumatic signals generated by multiplesolenoids, a single electric operator 94 can be provided in portion 76and mechanically coupled to valve 86. Generally, electrical devices suchas electric operator 94 or solenoids cannot be provided within theheated portion 74 since the heat would degrade, if not destroy, theelectrical components.

An emission sample from sample probe 82 is conveyed through heatedsection 74 of enclosure 72 through four-way valve 86, through filter 88,to thermoelectric cooler 90. Since thermoelectric cooler 90 is disposedrelatively closely to heated portion 74, a heated line is not requiredfor embodiments of the present invention. Specifically, unheated sampleline such as one quarter inch diameter tubing can be used to convey thesample from valve 86 to thermoelectric cooler 90. Preferably, the sampletubing is formed of a chemically inert material such aspolytetrafluoroethylene (PTFE) such as that available from E. I. du Pontde Nemours and Company, under the trade designation Teflon. The cost ofsuch tubing is approximately $2.00 to $3.00 per foot. Preferably, thissample line runs from the probe enclosure to the analyzer enclosurewhich is generally a small 19 inch rack. Condensation fromthermoelectric cooler 90 is drained with the assistance with peristalticpump 96, and the sample is conveyed from thermoelectric cooler 90 to theanalyzer with the assistance of sample pump 98 at a rate of preferably 2to 3 liters per minute. A back pressure relief valve 100 is alsoprovided to relieve excess back pressure.

System 70 can also receive a calibration standard through line 102 whichis coupled to four-way valve 86. Preferably, system 70 includes checkvalve 104 interposed upon line 102 between the analyzer and four-wayvalve 86. Check valve 104 prevents contamination of the calibration lineand the calibration cylinder.

The above-described sample handling system 70 can be easily installed orreplaced in typically less than 20 minutes and is not a high maintenanceitem due to its simplified, efficient design. System 70 can require lessthan one hour to install, and complete start-up can generally beachieved in less than four hours. Typical sample handling systems suchas that shown in FIG. 2 and described previously, generally require oneweek of installation and three to four days before start-up can beachieved. Moreover, system 70 can generally be designed to weigh lessthan 50 pounds thereby facilitating transportation. In contrast,conventional sample handling systems often weigh over 300 pounds, arebulky, large and require special transportation and special handling.Further still, conventional sample handling systems require both highpressure air and electrical power. In contrast, system 70, as describedabove, requires only electrical power and low pressure nitrogen or airfor blow-back. As an illustration of the improved, simplified design ofembodiments of the present invention, system 70 can be designed to costapproximately $2,700.00 where conventional sample handling systemstypically cost in the neighborhood of $16,500.00.

FIG. 4 is a diagrammatic view of an analyzer in accordance with anembodiment of the present invention. Analyzer 200 can be used withsample handling system embodiments set forth above, such as in place ofanalyzer 16, or can be used with conventional sample handling systems.Analyzer 200 is generally provided within an enclosure 202 and receivessample gas through line 204 which is coupled to a sample handling systemsuch as line 101 of sample handling system 70 (shown in FIG. 3).

Additionally, analyzer 200 includes calibration source gases 206 whichcan be selectively provided to a sample handling system, such as samplehandling system 70 via line 208. Sample gas is received on line 204 andpasses through flow meter 210 which provides a signal to CentralProcessing Unit (CPU) 212, which signal is related to sample gas flowpassing through flowmeter 210. In one embodiment, after passing throughflowmeter 210, sample gas passes through a paramagnetic oxygen detectorwhich is specifically adapted to measure oxygen in the 0 to 20′ rangeand provide a signal related to oxygen concentration to CPU 212. Afterpassing through oxygen detector 214, sample gas passes throughNon-Dispersive Infrared Detector 216 which provides a signal to CPU 212that is related to carbon oxides in the 0 to 100 parts-per-millionrange. Finally, sample gas is conveyed to Chemiluminescent nitrogenoxide detector 218. Detector 218 provides a signal to CPU 212 based uponthe quantitative presence of nitrogen oxide in the 0 to 100parts-per-million range. After passing through detector 218, sample gasvents through vent 220.

In this embodiment, CPU 212 receives signals from flowmeter 210,paramagnetic oxygen detector 214, NDIR detector 216 and Chemiluminescentdetector 218 at analog inputs 222. CPU 212 may also preferably receivenumerous inputs from the engine as described later. Inputs 222 arecoupled to a multi-channel analog-to-digital converter 224. Preferably Ato D converter 224 has a relatively high resolution (20-24 bits orhigher) and is used to improve signal-to-noise ratio of the underlyinganalytical measurements. The signal-to-noise ratio can be measuredonline and automatically optimized by adjusting digital filterparameters either at initial setup, during auto-calibration, orcontinuously online.

CPU 212 preferably includes an embedded control system such as a PC 104.In this particular embodiment, the PC includes a microprocessoroperating at approximately 100 MHz. CPU 212, and all other components ofanalyzer 200, preferably receive electrical power via input 231. Thispower is conveyed to power supply 234 which typically reduces thevoltage to a 24 volt DC power supply which provides 24 volts DC to thevarious components of analyzer 200. The embedded PC 104 system iscommercially available. CPU 212 also preferably includes a display 226,such as a color LCD touch-pad display, a PCMCIA interface 228, and aprinter port 230. Additionally, CPU 212 provides a number of outputssuch as serial data output 232 which can provide serial data in anysuitable form, such as RS232 to a customer supplied device such as aProgrammable Logic Controller. (PLC) or Data Acquisition System (DAS).

Although one output of CPU 212 is described as serial data emanatingfrom serial port 232, additional outputs can be provided such as, forexample data in any suitable format conveyed over radio, wire,fiber-optic, or cellular phone communications. Such data can provide,for example, reports, alarms, generators/power system diagnostics,instrument diagnostics and analytical data as well as received controlsignals. The data can facilitate system self-diagnostics and remotemonitoring. The computational power of CPU 212 allows the measurementsprovided by flowmeter 210 and detectors 214, 216 and 218 to be used todetermine process and/or power system energy and/or plant efficiencyand/or capacity as will be described in greater detail below. Thesequantities can be used to maximize efficiency by adjusting controlsusing gradient-based, search-based, or other optimization techniques.This data can also be used to adjust or control the engine or generatorto thereby reduce or maintain emission levels at or below environmentalrestrictions or other constraints.

In one embodiment, CPU 212 preferably provides analog outputs in the 4to 20 milliamp regime corresponding to oxygen percentage, carbonmonoxide parts-per-million, and nitrogen oxide parts-per-million.Further still, CPU 212 can provide multiple TTL inputs and outputs. TTLinputs can be used to manually initiate auto-calibration. TTL outputscan provide signals that indicate system faults, carbon monoxideparts-per-million exceeding a selected threshold, nitrogen oxideexceeding a selected threshold, and a signal indicating that the systemis in need of calibration. Further still, digital outputs relating tozero calibration, midpoint calibration, span calibration, purge control,calibration control and pump control can be provided as well.

Although the sample probe used for embodiments of the present inventioncan include conventional sample probes, sample probe 82 can be designedto use semi-permeable membranes to separate out particulates fromexhaust gases to process gases to be analyzed. Additionally, a sweptcarrier gas can be provided proximate the semi-permeable membranes tothereby preclude direct sampling of the emission. This indirect samplingeliminates corrosion or condensation problems that result from somecontact with process or exhaust gases.

Control and Operation

FIG. 5 is a system block diagram of a system for generating electricityin accordance with an embodiment of the present invention. Powerplant100 includes fossil fuel engine 102 coupled to generator 104 such thatoperation of engine 102 generates electricity which is provided toswitch-fuse 106 on line 108. Switch-fuse 106 selectively provideselectricity from generator 104 to distribution grid 110 and provides afusible link between the generator and the distribution grid.

Fossil fuel engine 102 operates based upon a number of inputs includingmanual inputs and soft inputs. Examples of manual inputs include a startsignal such as an operator pressing a start button, a start signal beingprovided by a remote operator, a shut-down signal, and a throttlesignal. Examples of soft inputs include data about what physically isbeing provided to the engine such as the fuel level, fuel consumptionrate, fuel composition, fuel filter, and the fuel-air mixture. Asdescribed above, emission control of engine 102 is of primary concernand thus an emission monitoring system 120 is preferably employed.

Emission monitoring system 120 is preferably located near engine 102 andis able to sample emissions from the exhaust stack or exhaust port andcan sense emission characteristics such as oxides of nitrogen, oxides ofcarbon, and oxygen. Further, emission monitoring system 120 can alsopreferably monitor unburned fuel in the emission stream emission volume,emission heat, and even emission noise. Another parameter that can bemonitored is the fuel composition itself. For example, diesel fuel isavailable in different mixes, and such mixes may require differentengine operational characteristics. By determining fuel composition,system 120 can provide suitable outputs to the engine in order to ensureproper operation. Emission monitoring system 120 can also be providedwith engine data such as engine RPM (revolutions per minute), hoursremaining before engine 102 is due for overhaul, engine throttleposition, engine oil pressure, engine temperature, and engine oil level.System 120 can also receive data on the electricity generated (low powerfactor power).

Preferably, monitoring system 120 employs predictive emission monitoringas set forth in U.S. Pat. No. 5,970,426, which patent is assigned to theAssignee of the present invention, and is incorporated herein byreference. Using combined predictive monitoring and measured emissionmonitoring provides enhanced accuracy and maintenance. However, usingeither method alone allows for an element of redundancy. Monitoringsystem 120 also preferably includes an interface to allow remoteperformance monitoring, control, and administration of multiplegenerators 100 as will be described in greater detail later in theSpecification. As illustrated, emission monitoring system 120 includes awireless interface 122 and local area network (LAN) interface 124. Thoseskilled in the art will appreciate that a number of options exist forcommunicating with remote locations, and all such options are expresslycontemplated. One feature which facilitates remote operation andadministration of such generators or powerplants is that at least one ofinterfaces 122 and 124 is coupled to a global computer network such asthe Internet 126.

This arrangement allows remote monitoring and control node 128 to coupleto engine 102 and generator 104 via an internet service provider 130.Preferably, node 128 includes suitable software to allow node 128 tofunction as an application service provider. An application serviceprovider, as defined herein, is an entity, such as a business, thatprovides remote access to an application program across a networkprotocol. Moreover, node 128 can be designed to allow a user tosimultaneously control, monitor, and calibrate simultaneous operation ofa multitude of systems 100. More importantly, embodiments of the presentinvention allow automated reporting to the EPA on such generatoremissions, as indicated by arrow. This significantly reducesadministrative costs and facilitates cost effective power generation.Using the data provided to monitoring system 120, a remote operator 152can interface with a generator or engine through node 128 in order tomonitor and control a vast array of powerplant and power gridoperational characteristics and system wide controls, as indicated byarrow 154. Such characteristics include, but are not limited to, fuelconsumption, electrical loading of system 100, anticipating peak demandtimes, historical use of system 100, line stability in terms of voltagefluctuation, phase balance of the produced electricity, reflectionspresent on the power grid, operational time restrictions, reportingparameters such as sending data automatically to system owners and/orfederal regulators, system maintenance report generation, emergencyshut-downs, initiation of auxiliary cooling, and load-flow calculations.Further still, node 128 can allow remote operator 152 to monitorcharacteristics of individual units such as unit fuel level, fuelcapacity unit alarms, unit diagnostics, and other suitable parameters.

Remote operator 152 can also monitor an entire bank of systems 100simultaneously. Such monitoring allows calculation of reserve powercapacity of all generators both individually and in combination,calculation of profitability of operating individual units, the bank ofunits, or portions thereof, calculation of percent capacity ofindividual generators in use, power factor correction, and costs perkilowatt of produced electricity.

Remote operation and monitoring through node 128 also allows the user toactivate individual systems 100 based upon external information such asthe geographical location of each individual powerplant such thatgeneration costs versus electrical transportation costs can be balanced.An example of this is if the operator knows that a specific region isundergoing peak demand for electricity, operation of generators in thatgeneral vicinity can be initiated first based upon all parameters tothereby reduce the cost of generating and transporting electricity tothat region. By understanding operational costs such as fuel consumptionand system maintenance cost, node 128 can facilitate a payment system toautomatically receive or provide payments based upon the operation ofone or more generators. Finally, a remote operator, or the node 128, canrequest fuel delivery to the powerplant either manually or automaticallyand specify quantity and/or quality of fuel to be delivered to each andevery system 100 via electronic communication. Node 128 or an individualcan also generate requests for scheduled maintenance upon individualpowerplants via the Internet.

Distributed Monitoring and Control

FIG. 6 is a system block diagram of a generating system in accordancewith an embodiment of the present invention. System 300 includesgenerators 302, each of which is coupled to the Internet 304 via localcontrollers 306. Although each of generators 302 is illustrateddiagrammatically as a small power plant, in reality such generators cantake any form including, electrical generators coupled to such primarypower sources as reciprocating diesel engines, reciprocating gasengines, gas turbines, steam turbines, package boilers and waste heatboilers. Further, generator 302 can also take the form of solar-basedgenerators, wind-based generators, fuel-cell based generators, or anyother suitable device that is capable of transforming any form ofpotential energy into electricity. Preferably, local controllers 306take the form of CPU 212 described above. Thus, controllers 306 are eachadapted to provide local monitoring and control intelligence for itsassociated generator. Each of local controllers 306 is also preferablyadapted to sense the phase of the power grid to which the generator isattached and control the generator such that the phase of the generatedelectricity matches that of the grid. As illustrated in FIG. 6, each oflocal controllers 306 is coupled to monitor and control node 308 viainternet 304. Local controllers 306 can take the form of CPU 212described above. This is simply a preferred arrangement since it allowsa virtually infinite number of control nodes 308 to be coupled togenerators 302 at virtually any location in the world. However, inembodiments where control node 308 is located suitably close togenerators 302, various other communications can be used. For example,generators 302 can be coupled to monitor and control node 308 viawireless, wired, or fiber optic communications. Regardless of the mannerin which local controllers 306 are coupled to control node 308, thearrangement provides for the abilities to remotely start, run anddispatch generated power to the grid from nodes 308. Generators 302preferably include suitable detection devices such as temperature,pressure, differential pressure, mass flow and analytical detectiondevices to determine such quantities as composition, heating value andcost of fuel, for example. Additionally, by also measuring power output,power generation unit costs and thermal efficiency can be calculatedprovided to the user.

Using the improved dispatch, control, and monitoring system inaccordance with embodiments of the present invention facilitateshigh-level emission monitoring and control. For example, the data fromindividual generators 302 can be provided to a centralized controllersuch as node 308 that can be adapted to perform area monitoring andprovide data to allocate the deployment, operating level, and otherappropriate parameters to reduce aggregate or maximum area pollutionlevels or to maximize power production within an allowable area (e.g.the bubble concept) pollution levels (maximum or area aggregateaverage). Further still, Light Detection And Ranging (LIDAR) scanningenvironmental quality monitoring equipment and/or multiple stationaryenvironmental monitoring stations (not shown) can take emissions datainto a local or remote environmental quality measurement, mapping,management, control and optimization system. This data can be used toautomatically control and select the generators that are on-line. Thisensures that only those generators that would not cause the environmentto exceed established limits are operated. Alternatively, individualunits could be controlled and/or selected such that the mix ofgeneration and operating point for each resource is optimized tominimize aggregate environmental pollution.

Information about the combustion process in fossil-fuel based generatorscan also be conveyed via the Internet and calculations can be stored andperformed by an Internet server or other suitable service. Further, thevarious devices to which CPU 212 can be coupled either directly or via aglobal computer network can assist in the optimization process andthereby provide communications related to optimization via an internetapplication service provider server. The sophistication of analyzer 200allows the entire system, including the engine to be remotely monitoredand/or controlled either from a control room or even from an electricalgrid in response to central energy management controls.

Although communication node 304 is illustrated as the Internet, anysuitable medium can be used to couple the local controllers 306 tomonitor and control node 308. The Internet is preferred because itallows a virtually infinite number of control nodes 30B to be coupled togenerators 302 at virtually any location in the world. However,communication node 304 can take a variety of forms such as internet,intranet, virtual LAN, etc.

For embodiments where the primary power source for a generator is basedupon fossil-fuel combustion, it is preferred that the generator includea continuous emission monitoring system such as that disclosed above.Further still, it is preferred that emissions calculations for suchcontinuous emission systems be shared among local controllers 306 oreven control nodes 308. Those skilled in the art will recognize that thedistributed control and monitoring system illustrated in FIG. 6facilitates acquisition of local sensor data, such as unprocessedemissions sensors and communication to additional devices such as othercontrollers 306 or control node(s) 308 such that a shared computingresource is used to calculate generation parameters. Control node 308can also include an application service provider as discussed above.These calculations can be used to optimize an individual generator 302while minimizing or at least reducing its emissions. Emissions can beautomatically reported to suitable authorities via the internet or othercommunication methods and operating data can be monitored globally viathese same communication methods.

It is appreciated that the above-described system can be used tofacilitate various optimizations in generator operation. For example,embedded model-based optimization of the generating equipment can beused to minimize pollutants such as oxide nitrogen and carbon as well asmaximize generating efficiency by adjusting generating equipmentparameters. Such parameters include, but are certainly not limited to,excess air, operating temperature, and timing, depending on the natureof the generating equipment. As described above, various processes andtechniques can be used to relate individual, or combinations of sensorinformation for minimization of emissions or optimization of generatorefficiency. Such maximization of generator efficiency can be done usingvector gradient or other techniques known in the art. This optimizationcan optionally run on local microprocessor(s) (such as the embedded PC'sdescribed above) and provide redundancies. Alternately, the optimizationcan be executed remotely by a server over a global network, such as theinternet. The internet can also be used a back-up means for bothoptimization and control should the local capability be unavailable forany reason.

Further, on-site measurement or monitoring of key generating equipment,analytical sensors or controllers (including self-diagnosis by theequipment) can determine and report operating health of the generatingequipment, sensors or controllers and conceivably even predict time tofailure. Such measurements and predictions can be provided to suitablepersonnel to automatically dispatch such persons as well as provide dataregarding parts, equipment, and other resources needed to perform theanticipated maintenance. Further, the system can provide a fail-softcapability such that when aberrant operation is detected, the controls(either local or remote) can be used to initiate particular operatingmodes of the generator, which modes will prolong the generator lifeuntil it can be serviced.

Alternatively, the control and optimization could be executed via ashared remote server at the dispatch site or elsewhere. Anotheralternative is to utilize a remote application server provider (ASP) toexecute the control and optimization and CEMS calculations, andreporting, monitoring (alarms, operator guides, etc.) and to deliversuch control, optimization and monitoring information via the internet,virtual LAN, or other communication means.

Although embodiments have been described with respect to specificprocess variables being used for generator optimization, it is expresslycontemplated that any number of variables including, but not limited to,carbon monoxide levels, nitrogen oxide levels, sulfurous oxide levelsand oxygen could be used to facilitate any or all of the following:emission compliance, combustion optimization, power output maximization,emission control through power source optimization, emission control byaddition of suitable agents such as nitrogen oxides, adsorbents ofsulfurous oxides, steam or water. Any suitable variables for eachgenerator can also be adjusted for any of the above purposes. Forexample, the fuel feed rate, timing, air/fuel ratio, temperature, andamount of steam injection could be varied to provide the aboveadvantages.

Efficiency

The economics of large-scale implementation of micro power generatorsand controllers would be improved if the efficiency of such systemscould be enhanced. Pursuant to another aspect of this invention, thewaste heat flowing from the powerplant itself could be put to additionaluse. For example, many of the facilities listed above with excessgenerating capacity, also employ air conditioning systems, especially inlocations with warmer climates. A relatively recent innovation in airconditioning systems is the hydride heat pump. An example of a hydrideheat pump system is set forth in U.S. Pat. No. 5,497,630. A hydride heatpump system is an alternative to traditional vapor compression andabsorption refrigeration systems. One of the primary advantages ofhydride heat pump systems is that they do not use refrigerants such asozone-depleting chloro-fluoro-carbon refrigerants (CFC's). In hydrideheat pump systems, a low temperature metal hydride (a refrigeranthydride) is coupled to a high temperature hydride (the regeneratorhydride) permitting energy to be extracted from the refrigerated space.The energy absorbed at low temperature during the refrigeration stepdissociates hydrogen from the refrigerant hydride where it flows intothe regenerator hydride, which is at a lower pressure. The hydride heatpump system does not include any moving parts and operates usingvirtually any heat source.

FIG. 7 is a diagrammatic view of a power generating system and heat pumpsystem operating in accordance with an embodiment of the invention.Engine 102 is coupled to generator 104 as described previously withrespect to FIG. 5. CEMS 120 is coupled to both engine 102 and generator104 in accordance with embodiments of the invention described above.Unlike previous embodiments, however, FIG. 7 illustrates metal hydrideheat pump system 180 thermally coupled to stack or exhaust port 12.Embodiments of the invention described herein essentially thermallycouple the waste heat from the electricity generating source (engine102) to hydride heat pump system 180 to take further advantage of energyotherwise lost during power generation.

One of the synergies created by the combination of the metal hydrideheat pump system 180 and continuous emission monitoring system 120described above is that changes and/or deteriorations in the internalchemistry, or other parameters of interest, within the metal hydrideheat pump system can be detected and/or controlled. This optionalfeature is illustrated as dashed line 182 in FIG. 7. CEMS 120 employs anumber of relatively sophisticated sensors, and can easily be scaled toinclude additional sensors that sense parameters of interest withinmetal hydride heat pump system 180. Moreover, since the heat source forthe metal hydride heat pump system is the waste stream itself flowingthrough stack or exhaust port 12, it is possible to remove particularcomponents from a combustion waste stream to thereby continually, orperiodically, regenerate the internal chemistry within the metal hydrideheat pump 180. Thus, maintenance of the metal hydride heat pump 180could be reduced and the longevity thereof could be increased.

Although the invention has been described with reference to preferredembodiments, workers skilled in the art will recognize that changes canbe made in form and detail without departing from the spirit and scopeof the invention.

1. A Continuous Emission Monitoring System for fossil fuel basedgenerators, the system comprising: an analyzer adapted to receive asample flow and provide an output indicative of at least one constituentof the sample flow; a sample handling system coupleable to an emissionsource and adapted to extract an emission sample from the sample sourceand provide the extracted emission sample to the sample analyzer; andwherein the sample handling system is embodied within a single enclosuredisposed externally to the emission source, wherein the single enclosurehas two compartments which are maintained at different temperatures withrespect to one another.
 2. The system of claim 1, wherein the firstcompartment includes a sample probe and valve, and wherein the firstcompartment is maintained at an elevated temperature, and wherein thesecond compartment includes a thermoelectric cooler.
 3. The system ofclaim 2, wherein non-heated tubing connects the valve to thethermoelectric cooler.
 4. The system of claim 1 whereinpolytetrafluoroethylene tubing conveys a sample from a sample probe tothe analyzer.